<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        span{
            position: absolute;
            top: 300px;
            background-color: rebeccapurple;
            width: 200px;
            height: 150px;
        }
        div{
            position: absolute;
            background-color: skyblue;
        }
        /* 行内元素添加绝对或则固定定位，可以直接设高度和宽度 
        块级元素添加绝对或者2相对定位，如果不给宽度和高度，默认大小是内容的大小
        浮动元素绝对定位的元素都不会触发外边距合并
        */

    </style>
</head>
<body>
    <span>123</span>
    <div>asd</div>
</body>
</html>